Ophthalmic and aural compositions containing diclofenac potassium

ABSTRACT

The present invention describes an ophthalmic composition diclofenac potassium, the use of said composition as a medicament for treating inflammatory conditions of the eye, for treating glaucoma or for treating ear inflammatory conditions and/or painful conditions (otitis)-l as well as the use of diclofenac potassium in the preparation of a pharmaceutical composition for the treatment of any inflammatory condition of the eye, for treating glaucoma or for treating ear inflammatory and/or painful conditions (otitis).

This application claims priority to European Patent Application No. 95/03844, filed on Sep. 28, 1995.

The present invention describes an ophthalmic composition comprising diclofenac potassium, the use of said composition as a medicament for treating inflammatory conditions of the eye, for treating glaucoma or for treating ear inflammatory and/or painful conditions (otitis); as well as the use of diclofenac potassium in the preparation of a pharmaceutical composition for treating any inflammatory condition of the eye, for treating glaucoma or for treating ear inflammatory and/or painful conditions (otitis).

Hitherto, predominantly corticosteroids have been used for the treatment of relatively severe acute or chronically recurrent inflammatory symptoms in the eye. The immunosuppressant action of these substances, however, conceals the risk of a deterioration in the clinical picture as a result of a bacterial or viral infection. Therefore, considerable efforts are still made, to develop potent non-steroidal anti-inflammatory agents and to introduce them into ophthalmological therapy.

EP 242 328 describes for example a medicament for the treatment of inflammations of the eye, which medicament comprises sodium 2- (2,6-dichlorophenyl)amino!-phenyl acetate, known as diclofenac sodium.

Diclofenac-potassium, is chemically described as potassium 2- (2,6-dichlorophenyl)amino!-phenyl acetate. It is known as a non-steroidal anti-inflammatory drug (NSAID). A Norwegian publication, Cephalalgia 13, 117-123(1993), describes for example the use of diclofenac potassium in the acute treatment of migraine.

A stabilized aqueous solution of pharmaceutically acceptable salts of 2- (2,6-dichlorophenyl)amino!-phenyl acetic acid for ophthalmic use is disclosed in U.S. Pat. No. 4,960,799. Diclofenac potassium is not specifically disclosed in said application. Accordingly, all claims and working examples of said application disclose either diclofenac sodium or its free acid as a pharmaceutically active ingredient. Hence, said application is clearly directed towards the provision of a stable aqueous solution of a pharmaceutically acceptable salt of 2- (2,6-dichlorophenyl)amino!-phenyl acetic acid containing an effective amount of a pharmaceutically acceptable salt of ethylenediamine tetraacetic acid.

Surprisingly it was found, that the potassium salt of 2- (2,6-dichlorophenyl)amino!-phenyl acetic acid, diclofenac potassium, is especially suitable to treat inflammatory ocular processes in general. It has been demonstrated that for example the ocular penetration of diclofenac potassium is much superior in comparison to the corresponding diclofenac sodium. In addition to said advantage, pharmacological studies show a much better topical tolerance, e.g. ocular tolerance, and efficacy of diclofenac potassium in comparison to diclofenac sodium and also a surprisingly short onset of action as well a long lasting duration of action e.g. in the eye.

Therefore the present invention relates to an ophthalmic composition for treating inflammatory ocular conditions, for treating glaucoma or for treating ear inflammatory and/or painful conditions (otitis), which composition comprises a therapeutically effective amount of diclofenac potassium and a carrier.

The present invention relates also to an ophthalmic composition for treating inflammatory conditions of the eye, which composition comprises a therapeutically effective amount of diclofenac potassium and a carrier.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium, a carrier and a stabilizer.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium, a carrier and a solubilizer.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium, a carrier, a stabilizer and a solubilizer.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclotenac potassium, a carrier, a solubilizer, a stabilizer and a complexing agent.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium, a carrier, a solubilizer, a stabilizer, a complexing agent and a tonicity enhancing agent.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium, a carrier, a solubilizer, a stabilizer, a complexing agent, a tonicity enhancing agent and a buffer.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium, a carrier, a solubilizer, a stabilizer, a complexing agent, a tonicity enhancing agent, a buffer and a preservative.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium and a carrier, and is further comprising one or more of the excipients selected from the group consisting of buffers, complexing agents, tonicity enhancing agents, preservatives and fillers.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium, a carrier and a stabilizer, and is further comprising one or more of the excipients selected from the group consisting of buffers, complexing agents, tonicity enhancing agents, preservatives and fillers.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium, a carrier and a solubilizer, and is further comprising one or more of the excipients selected from the group consisting of buffers, complexing agents, tonicity enhancing agents, preservatives and fillers.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium, a carrier, a solubilizer and a stabilizer, and is further comprising one or more of the excipients selected from the group consisting of buffers, complexing agents, tonicity enhancing agents, preservatives and fillers.

Another aspect of the present invention is the use of diclofenac potassium and a carrier in the preparation of a pharmaceutical composition for treating inflammatory ocular conditions, for treating glaucoma or for treating ear inflammatory and/or painful conditions (otitis).

The present invention relates also to the use of diclofenac potassium and a carrier in the preparation of a pharmaceutical composition for treating inflammatory ocular processes.

The present invention relates also to the use of diclofenac potassium, a carrier and a stabilizer in the preparation of a pharmaceutical composition for treating inflammatory ocular conditions, for treating glaucoma or for treating ear inflammatory and/or painful conditions (otitis).

The present invention relates also to the use of diclofenac potassium, a carrier, a stabilizer and a solubilizer in the preparation of a pharmaceutical composition for treating inflammatory ocular conditions, for treating glaucoma or for treating ear inflammatory and/or painful conditions (otitis).

Still another aspect of the present invention is a method of treating inflammatory ocular conditions, which method comprises administering topically to the eye of a patient requiring such treatment a therapeutically effective amount of an ophthalmic composition comprising diclofenac potassium and a carrier.

The present invention relates also to a method of treating inflammatory ocular conditions, which method comprises administering topically to the eye of a patient requiring such treatment a therapeutically effective amount of an ophthalmic composition comprising diclofenac potassium, a carrier and a stabilizer.

The present invention relates also to a method of treating inflammatory ocular conditions, which method comprises administering topically to the eye of a patient requiring such treatment a therapeutically effective amount of an ophthalmic composition comprising diclofenac potassium, a carrier, a stabilizer and a solubilizer.

In the present invention, treating inflammatory ocular conditions means, treating all ophthalmological diseases involving inflammatory processes, whatever the causes are.

Examples for such causes are e.g. allergic or non-allergic inflammation, immune and non-immune processes, acute or chronic disease. Examples for such treatments of ocular inflammations are the inhibition of miosis during ocular surgery, prevention or treatment of ocular pain during these processes or consequent upon surgery, inhibition of photophobia, treatment of uveitis or ocular inflammation of any cause and the like. Post operative inflammations are for example, of the type associated with cataract removal or photorefractive surgery or incisional refractive surgery, trabeculectomy and combined procedures thereof, painful eye-conditions (including photophobia and post-operative pain), pain associated with trauma or foreign bodies, prevention and treatment of macular edema (idiopathic or associated with surgical interventions or diabetes) and inhibition of miosis.

According to the present invention an ophthalmic composition may also be used for treating glaucoma in connection with non-inflammatory induced elevated intraocular pressure associated with administered or endogenous glucocorticoids.

According to the present invention an ophthalmic composition may also be used for treating ear inflammatory and/or painful conditions (otitis).

According to the present invention an ophthalmic composition may preferably be used for treating inflammatory ocular conditions.

According to the invention an ophthalmic composition is advantageously applied topically to the eye, especially in the form of a solution, a suspension, an ointment, a gel or a solid insert. Such compositions comprise the active ingredient, for example, in a range of from approximately 0.000001 to approximately 5.0% by weight, preferably from approximately 0.001 to approximately 1.0% by weight, or more preferably in the range of from approximately 0.01 to approximately 0.5% by weight and most preferably in the range of from 0.025 to 0.1% by weight. The dose of the active ingredient may depend on various factors, such as mode of administration, requirement, age and/or individual condition. Analogously an above ophthalmic composition may be also topically applied to an ear.

There are used for a corresponding ophthalmic composition customary pharmaceutically acceptable excipients and additives known to the person skilled in the art, for example those of the type mentioned below, especially carriers, stabilizers, solubilizers, tonicity enhancing agents, buffer substances, preservatives, thickeners, complexing agents and other excipients. Examples of such additives and excipients can be found in U.S. Pat. Nos. 5,134,124 and 4,906,613. Such compositions are prepared in a manner known per se, for example by mixing the active ingredient with the corresponding excipients and/or additives to form corresponding ophthalmic compositions. The active ingredient is preferably administered in the form of eye drops, the active ingredient being conventionally dissolved, for example, in a carrier. The solution is, where appropriate, adjusted and/or buffered to the desired pH and, where appropriate, a stabilizer, a solubilizer or a tonicity enhancing agent is added. Where appropriate, preservatives and/or other excipients are added to an ophthalmic composition.

Carriers used in accordance to the present invention are typically suitable for topical or general administration, and are for example water, mixtures of water and water-miscible solvents, such as C₁ - to C₇ -alkanols, vegetable oils or mineral oils comprising from 0.5 to 5% by weight hydroxyethylcellulose, ethyl oleate, carboxymethylcellulose, polyvinylpyrrolidone and other non-toxic water-soluble polymers for ophthalmic uses, such as, for example, cellulose derivatives, such as methylcellulose, alkali metal salts of carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, methylhydroxypropylcellulose and hydroxypropylcellulose, acrylates or methacrylates, such as salts of polyacrylic acid or ethyl acrylate, polyacrylamides, natural products, such as gelatin, alginates, pectins, tragacanth, karaya gum, xanthan gum, carrageenin, agar and acacia, starch-derivatives, such as starch acetate and hydroxypropyl starch, and also other synthetic products, such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, polyethylene oxide, preferably cross-linked polyacrylic acid, such as neutral Carbopol, or mixtures of those polymers. Preferred carriers are water, cellulose derivatives, such as methylcellulose, alkali metal salts of carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, methylhydroxypropylcellulose and hydroxypropylcellulose, neutral Carbopol, or mixtures thereof. The concentration of the carrier is, for example, from 1 to 100 000 times the concentration of the active ingredient.

The solubilizers used for an ophthalmic composition of the present invention are, for example, tyloxapol, fatty acid glycerol poly-lower alkylene glycol esters, fatty acid poly-lower alkylene glycol esters, polyethylene glycols, glycerol ethers vitamin E and vitamin E derivatives, such as Vitamin E Tocopherol Polyethylene Glycol 1000 Succinate (TPGS) or mixtures of those compounds. A specific example of an especially preferred solubilizer is a reaction product of castor oil and ethylene oxide, for example the commercial products Cremophor EL® or Cremophor RH 40®. Reaction products of castor oil and ethylene oxide have proved to be particularly good solubilizers that are tolerated extremely well by the eye. Another preferred solubilizer is tyloxapol. The concentration used depends especially on the concentration of the active ingredient. The amount added is typically sufficient to solubilize the active ingredient. For example, the concentration of the solubilizer is from 0.1 to 5000 times the concentration of the active ingredient.

According to the present invention lower alkylene means linear or branched alkylene with up to and including 7 C-atoms. Examples are methylene, ethylene, 1,3-propylene, 1,2-propylene, 1,5-pentylene, 2,5-hexylene or 1,7-heptylene.

Lower alkylene is preferably linear or branched alkylene with up to and including 4 C-atoms.

Examples of buffer substances are acetate, ascorbate, borate, hydrogen carbonate/carbonate, citrate, gluconate, lactate, phosphate, propionate and TRIS (tromethamine) buffers. Tromethamine and borate buffer are preferred buffers. The amount of buffer substance added is, for example, that necessary to ensure and maintain a physiologically tolerable pH range. The pH range is typically in the range of from 5 to 9, preferably from 6 to 8.2 and more preferably from 6.8 to 8.1.

Tonicity enhancing agents are, for example, ionic compounds, such as alkali metal or alkaline earth metal halides, such as, for example, CaCl₂, KBr, KCl, LiCl, Nal, NaBr or NaCl, or boric acid. Non-ionic tonicity enhancing agents are, for example, urea, glycerol, sorbitol, mannitol, propylene glycol, or dextrose. For example, sufficient tonicity enhancing agent is added to impart to the ready-for-use ophthalmic composition an osmolality of approximately from 50 to 1000 mOsmol, preferred from 100 to 400 mOsmol, more preferred from 200 to 400 mOsmol and even more preferred from 280 to 350 mOsmol.

Examples of preservatives are quaternary ammonium salts, such as cetrimide, benzalkonium chloride or benzoxonium chloride, alkyl-mercury salts of thiosalicylic acid, such as, for example, thiomersal, phenylmercuric nitrate, phenylmercuric acetate or phenylmercuric borate, parabens, such as, for example, methylparaben or propylparaben, alcohols, such as, for example, chlorobutanol, benzyl alcohol or phenyl ethanol, guanidine derivatives, such as, for example, chlorohexidine or polyhexamethylene biguanide, or sorbic acid. Preferred preservatives are cetrimide, benzalkonium chloride, benzoxonium chloride and parabens. Where appropriate, a sufficient amount of preservative is added to the ophthalmic composition to ensure protection against secondary contaminations during use caused by bacteria and fungi.

The ophthalmic compositions may comprise further non-toxic excipients, such as, for example, emulsifiers, wetting agents or fillers, such as, for example, the polyethylene glycols designated 200, 300, 400 and 600, or Carbowax designated 1000, 1500, 4000, 6000 and 10 000. Other excipients that may be used if desired are listed below but they are not intended to limit in any way the scope of the possible excipients. They are especially complexing agents, such as disodium-EDTA or EDTA, antioxidants, such as ascorbic acid, acetylcysteine, cysteine, sodium hydrogen sulfite, butyl-hydroxyanisole, butyl-hydroxytoluene or α-tocopherol acetate; stabilizers, such as a cyclodextrin, thiourea, thiosorbitol, sodium dioctyl sulfosuccinate or monothioglycerol vitamin E and vitamin E derivatives, such as Vitamin E Tocopherol Polyethylene Glycol 1000 Succinate (TPGS); or other excipients, such as, for example, lauric acid sorbitol ester, triethanol amine oleate or palmitic acid ester. Preferred excipients are complexing agents, such as disodium-EDTA and stabilizers, such as a cyclodextrin. The amount and type of excipient added is in accordance with the particular requirements and is generally in the range of from approximately 0.0001 to approximately 90% by weight.

A cyclodextrin as is referred to within the present invention is either an α-, β- or γ- cyclodextrin itself, a derivative thereof, e.g. a partially etherified derivative as e.g. a hydroxyalkyl ether or a mixture thereof. Examples of cyclodextrin derivatives are alkylated, hydroxyalkylated, carboxyalkylated or alkyloxycarbonyl-alkylated α-, β- or γ- cyclodextrins. Other typical examples are carbohydrate derivatives of cyclodextrins such as mono- or diglycosyl-α-, β- or γ- cyclodextrin, mono- or dimaltosyl-α-, β- or γ- cyclodextrin or panosylcyclodextrin. Another parameter which describes the substitution pattern of a cyclodextrin derivative is the degree of substitution (d.s.). A cyclodextrin is composed of several glucose units which have three free hydroxy groups per glucose. Accordingly the d.s. may vary from 0.125 up to 3. In the latter case all free (γ-cyclodextrin has 24) hydroxy groups may be substituted, while in the former case only 1 may be substituted. Preferably the d.s. may vary from 0.125 to 1.5 and more preferably from 0.125 to 0.5.

Preferred cyclodextrins are β- and γ- ciclodextrin, derivatives and mixtures thereof.

Strongly preferred cyclodextrins are hydroxypropyl-β- ciclodextrin, hydroxypropyl-γcyclodextrin, dimethyl-β- cyclodextrin and dimethyl-γ- ciclodextrin.

The amount of a cyclodextrin used in accordance with the present invention may preferably range from 0.01-20% by weight, more preferably from 0.1-15 % by weight and even more preferably from 1-10% by weight.

The present invention relates also to an ophthalmic composition, which comprises a therapeutically effective amount of diclofenac potassium, a carrier, a solubilizer and another therapeutically effective pharmaceutical agent which may be, for example, an antibiotic, an antiallergic, an anesthetic, another antiphlogistic, a corticosteroide, an agent suitable for lowering intra-ocular pressure, or another drug.

Several animal models are used for the demonstration of the claimed therapeutic efficacy of the ophthalmic compositions comprising diclofenac potassium. In each animal model several ophthalmic reference drugs are administered for comparison.

In a first animal model, the ocular distribution and lens penetration of diclofenac potassium and diclofenac sodium is determined after multiple topical ocular administration of a corresponding eye drop composition. Hence 14C labelled eye drop material is topically administered to the eyes of chinchilla pigmented rabbits (5 instillations, 50 μl each, within 20 minutes). At regular intervals post-instillation (0.5, 1.5, 2.0 hours), the animals are sacrificed and both eyes are removed. Said eyes are microdissected and the ocular distribution of the radioactivity is measured by a standard scintillation beta counting method. The highest concentrations are found in the cornea, and in descending order in the aqueous humor, in the iris ciliary body and in the vitreous. According to this experimental setup, the diclofenac potassium treated animals clearly displayed higher levels of radioactivity in the aforementioned areas than the diclofenac sodium treated animals.

Another animal model is used for the comparison of the ocular anti-inflammatory efficacy of diclofenac potassium in comparison to diclofenac sodium, which model is the arachidonic acid induced uveitis in pigmented rabbits. Repeated instillations of arachidonic acid into the eye of rabbits induce an ocular inflammation, which inflammation significantly increases the flare level in the anterior chamber of rabbits. A laser cell flare meter (LCFM) is used for the quantification of said flare levels. This method is described by e.g. M. Kuchle et al., Ophthalmologe 91, 219(1994), and is a non-invasive method. It has been demonstrated, that the flare determination by LCFM reflects the amounts of proteins comprised in the aqueous humor. These proteins are commonly used as markers in assessing the degree of an inflammation. For the non-invasive evaluation of the efficacy of an anti-inflammatory drug, said drugs are administered by using two instillations one hour and 45 minutes before the induction of an arachidonic acid induced inflammation as described above. A control group of animals is treated with a single instillation of non-preserved saline (Unilarm®). The inflammation process is monitored during 6 hours post-inflammation by the above described LCFM measurements.

In a further animal model the ocular anti-inflammatory efficacy of diclofenac potassium is determined with a traumatic uveitis model. Uveitis is induced in said model by an argon laser iris photocoagulation in pigmented rabbits. Said iris photocoagulation is induced by 500 μm argon laser burns (power 750 mW, duration 0.1 sec). The inflammatory processes resulting therefrom are measured every 30 minutes after the laser induced photo-coagulation, by using the laser cell flare meter (LCFM) technique. For the evaluation of the efficacy of an anti-inflammatory drug, said drugs are again administered by two instillations, one hour and 45 minutes prior to the induction of an inflammation as described above. A control group of animals is treated with instillations of non-preserved saline (Unilarm®). Again the inflammation process is monitored during 6 hours.

In addition to the non invasive LCFM evaluation of the above mentioned animal model, an invasive evaluation is carried out. Therefore the rabbits are sacrificed one hour and in regular intervals after which said eyes have been subjected to the traumatic uveitis by photocoagulation, and the aqueous humor of said rabbit eyes is sampled. The aqueous protein levels, cell counts and prostaglandins (PGE2, PGD2, 6-keto PGF1α) which represent the degree of an inflammation are biochemically investigated and quantified.

Another animal model is used for the induction of a traumatic uveitis. It is the induction of a uveitis by the paracentesis of the anterior chamber of the rabbit eye. In analogy to the previously described laser induced uveitis model, drugs to be tested, are again administred prior to the paracentesis challenge. In this animal model, the animals are again sacrificed at regular intervals, and the inflammatory process is investigated by sampling the aqueous humor of the challenged rabbit eyes. The aqueous protein levels are again analyzed, quantified and then correlated with the degree of an inflammation.

In all the aforementioned animal models, there is clear evidence that animals which are treated with diclofenac potassium benefit from a better efficacy compared to the animals treated with diclofenac sodium.

Typical experimental procedures which illustrate the present invention, but are not intended to limit it in any way, are described below.

EXAMPLE 1

Formulation of diclofenac potassium eye drops (0.1%)

    ______________________________________     diclofenac potassium    1.00   mg/ml     thiomersal              0.04   mg/ml     boric acid              19.0   mg/ml     cremophor EL ® (polyoxyl 35 castor oil)                             50.0   mg/ml     tromethamine            6.0    mg/ml     deion. water ad.        1.0    ml     ______________________________________

EXAMPLE 2

Formulation of diclofenac potassium eye drops (0.05%)

    ______________________________________     diclofenac potassium 0.50   mg/ml     benzalkonium chloride                          0.05   mg/ml     disodium edetate     1.0    mg/ml     tyloxapol            1.0    mg/ml     γ-cyclodextrin 20.0   mg/ml     tromethamine         1.0    mg/ml     hydrochloric acid 10%                          1.3    mg/ml     sorbitol             46.0   mg/ml     deion. water ad.     1.00   ml     ______________________________________

EXAMPLE 3

Formulation of non-preserved uni-dose diclofenac potassium eye drops (0.1%)

    ______________________________________     diclofenac potassium  1.00   mg/ml     disodium edetate      1.0    mg/ml     tyloxapol             0.1    mg/ml     dimethyl-β-cyclodextrin                           40.0   mg/ml     tromethamine          1.0    mg/ml     hydrochloric acid 10% 1.3    mg/ml     sorbitol              41.0   mg/ml     deion. water ad.      1.00   ml     ______________________________________

EXAMPLE 4

Formulation of oily eye drops

    ______________________________________     diclofenac potassium    0.50    mg/ml     benzalkonium chloride   0.1     mg/ml     cremophor RH 40 ®, (polyoxyl 40 hydrogenated                             20.0    mg/ml     castor oil)     castor oil ad.          1.00    ml     ______________________________________

EXAMPLE 5

Formulation of an eye gel

    ______________________________________     diclofenac potassium     0.50 mg/g     thiomersal               0.04 mg/g     boric acid               1.8 mg/g     cremophor EL ® (polyoxyl 35 castor oil)                              4.0 mg/g     tromethamine             13.0 mg/g     carbomer 980             4.0 mg/g     deion. water ad.         1.00 g     ______________________________________

EXAMPLE 6

Formulation of an eye gel

    ______________________________________     diclofenac potassium   1.00 mg/g     benzalkonium chloride  0.1 mg/g     tyloxapol              1.0 mg/g     mannitol               30.0 mg/g     hydrochloric acid 10%  1.0 mg/g     disodium edetate       0.5 mg/g     chitosan               10.0 mg/g     deion. water ad.       1.00 g     ______________________________________

EXAMPLE 7

Formulation of an eye ointment

    ______________________________________     diclofenac potassium  1.00 mg/g     phenylethyl alcohol   5.0 mg/g     tyloxapol             1.0 mg/g     disodium edetate      0.5 mg/g     γ-cyclodextrin  20.0 mg/g     deion. water          140 mg/g     cetylstearyl alcohol  22.0 mg/g     liquid paraffin       207 mg/g     white petrolatum      462 mg/g     wool fat              141.5 mg/g     ______________________________________

EXAMPLE 8

Formulation of diclofenac potassium eye drops (0.05%)

    ______________________________________     diclofenac potassium       0.5 mg/ml     cremophor RH ® (polyoxyl 40 hydrogenated castor oil)                                0.6 mg/ml     tromethamine               1.0 mg/ml     disodium edetate           0.5 mg/ml     sorbitol                   49.0 mg/ml     benzalkonium chloride      0.15 mg/ml     hydrochloric acid 1N       5.1 mg/ml     water for injections ad    1.0 ml     pH                         7.53     osmolality (mOsmol):       317     ______________________________________

EXAMPLE 9

Formulation of diclofenac sodium eye drops (0.1%)

    ______________________________________     diclofenac sodium          1.0 mg/ml     cremophor RH ® (polyoxyl 40 hydrogenated castor oil)                                0.6 mg/ml     tromethamine               1.0 mg/ml     disodium edetate           0.5 mg/ml     sorbitol                   49.0 mg/l     benzalkonium chloride      0.15 mg/ml     hydrochloric acid 1N       5.52 mg/ml     water for injections ad    1.0 ml     pH                         7.49     osmolality (mOsmol):       308     ______________________________________

EXAMPLE 10

Formulation of an eye drop vehicle

    ______________________________________     cremophor RH ® (polyoxyl 40 hydrogenated castor oil)                               0.6    mg/ml     tromethamine              1.0    mg/ml     disodium edetate          0.5    mg/ml     sorbitol                  49.0   mg/ml     benzalkonium chloride     0.15   mg/ml     hydrochloric acid 1N      5.0    mg/ml     water for injections ad   1.0    ml     pH:                       7.53     osmolality (mOsmol):      301     ______________________________________

EXAMPLE 11

Formulation of diclofenac potassium eye drops (0.1%)

    ______________________________________     diclofenac potassium      1.0    mg/ml     cremophor RH ® (polyoxyl 40 hydrogenated castor oil)                               0.6    mg/ml     tromethamine              1.0    mg/ml     disodium edetate          0.5    mg/ml     sorbitol                  49.0   mg/ml     benzalkonium chloride     0.15   mg/ml     hydrochloric acid 1N      5.7    mg/ml     water for injections ad   1.0    ml     pH:                       7.35     osmolality (mOsmol):      314     ______________________________________

EXAMPLE 12

Changes in aqueous flares (expressed as the area under the kinetic curves (AUC)) for the arachidonic acid induced uveitis model, carried out in pigmented rabbits.

The drugs listed infra (including placebo) are applied topically (30 μl each) to the left eye of pigmented rabbits (chinchilla pigmented female rabbits) one hour before arachidonic acid instillations. Each opposite eye is instilled for control with 30 μl of the vehicle formulation of example 10. Before the instillation of arachidonic acid, the animals are anesthetized with intramuscular injections of 35 mg/kg ketamine (Imalgene 1000®, Rhone Merieux) and 15 mg/kg xylazine (Rompun-Bayer). Arachidonic acid (0.5% aqueous solution, freshly prepared before use) is then instilled into both eyes of the rabbits with a Hamilton syringe (twice 50 μl). A time interval of 5 minutes is kept between each instillation. The flares are then measured hourly, using an LCFM over a total period of 6 hrs after the arachidonic acid challenge. Before each measurement, the animals are freshly anesthetized with intramuscular injections of 35 mg/kg ketamine (Imalgene 1000®, Rhone Merieux) and 15 mg/kg xylazine (Rompun-Bayer), in order to completely immobilize the eyes. The LCFM method is similar to a slit lamp microscopy examination. The laser beam of a Kowa FC-1000 LCFM is scanning vertically within a distance of 0.6 mm towards the center of the anterior chamber. Each measurement lasts about 0.5 seconds. Such a measurement is repeated five times for each eye and the average of the photon counts is then calculated and plotted versus the observation time, which lasts in total 6 hours calculated from the induction of the inflammation. The results are summarized below, which show the integrated photon counts of the treated and of the control eyes (AUC(treated) and AUC(control)), representing the overall degree of said induced inflammation over said 6 hours. Accordingly a high AUC number represents a strong inflammation, whereas a low AUC number represents a low degree of inflammation.

The ratio, AUC(treated) divided by AUC(control), is calculated as well. A low ratio value represents a strong anti-inflammatory efficacy, whereas a ratio value of about 1 reflects the substantial absence of an anti-inflammatory effect.

    ______________________________________                                      Ratio                AUC(t)reated                           AUC(c)ontrol                                      AUC(t)/AUC(c)     Drug       Mean ± SEM                           Mean ± SEM                                      Mean ± SEM     ______________________________________     placebo group                1616 ± 130                           1793 ± 171                                      0.93 ± 0.09     (Unilarm ®)     diclofenac potas-                 99 ± 20                           1043 ± 186                                       0.1 ± 0.02     sium Example 8     diclofenac sodium                 558 ± 141                           1462 ± 270                                      0.46 ± 0.12     Example 9     ______________________________________

The AUC(treated) values show the superior efficacy of diclofenac potassium (example 8) in comparison to the efficacy of diclofenac sodium (example 9). The inflammation in the animal group receiving diclofenac potassium is almost totally suppressed. Taking into account the fact that the drug concentration of diclofenac sodium (example 9) is twice the concentration of diclofenac potassium (0.1% versus 0.05%), diclofenac potassium is considered to have more than five fold efficacy of diclofenac sodium.

EXAMPLE 13

Lens penetration and ocular distribution of diclofenac potassium and diclofenac sodium were determined after multiple topical ocular administration of corresponding 14-C labelled eye drop composition into the conjunctival sac of the right eye of pigmented rabbits.

At 0.5, 1.5, 2 hours post-instillation, 5 animals for each time-point and each treatment group were sacrificed and the radioactivity content (in ng-Eq/g of structure) in the cornea, aqueous humor, iris-ciliary body, vitreous, whole blood and plasma was measured. At 2 hours post-instillation, the left eyes were removed and the ocular distribution was measured by a standard scintillation beta counting method. The right lenses were used for autoradiography.

The areas under the curve (AUC: ng-Eq/g of structure versus time) were calculated and statistically compared.

The results indicated that the ocular penetration of diclofenac potassium is much superior in comparison to diclofenac sodium:

    ______________________________________                 Sampling                         AUC: (ng-Eq/g)                 time (hour)                         Mean = 5    SEM     ______________________________________     Example 8     0.5       58978       19724     14-C-diclofenac                   1.5       34385       3669     potassium     2.0       23114       4093     Example 9     0.5       30342       5721     14-C-diclofenac sodium                   1.5       20201       5061                   2.0       13840       3497     ______________________________________

Example 8

14-C-diclofenac potassium

    ______________________________________     AUC: (ng-Eq/g) * hour     Mean = 5           SEM     ______________________________________     61056              9131     ______________________________________

Example 9

14-C-diclofenac sodium

    ______________________________________     AUC: (ng-Eq/g) * hour     Mean = 5           SEM     ______________________________________     33782              3826     ______________________________________

The highest concentration were found for both studied drugs in the comea and in descending order in aqueous humor, iris-ciliary body and vitreous.

EXAMPLE 14

Eye drop formulations

    ______________________________________     diclofenac potassium                         1.00 mg   0.5 mg     tromethamine        1.00 mg   1.00 mg     propylene glycol    20.5 mg   20.5 mg     hydroxypropyl-γ-cyclodextrin                         20.0 mg   20.0 mg     disodium edetate    1.00 mg   1.00 mg     benzalkonium chloride                         0.06 mg   0.06 mg     hydrochloric acid 1N                         qs        qs     water for injections ad                         1.00 ml   1.00 ml     pH                  7.90      7.90     osmolality (mOsmol) 296       296     preservative efficacy (Ph. Eur.)                         A         A     ______________________________________

The European Pharmacopoeia (Ph. Eur.) describes an efficacy test for antimicrobial preservation. Accordingly a preserved solution is inoculated with micro-organisms, characterized in that 10⁵ to 10⁶ micro-organisms are contained in one milliliter of the challenged preparation. The inoculum used does not exceed 1% of the total volume of said preparation. Five micro-organisms are used for the challenge, each separately namely, pseudomonas aeruginosa, staphylococcus aureus, candida albicans and aspergillus niger. The challenged solutions are kept at room temperature and protected from light. At regular time intervals samples are removed and the number of viable micro-organisms is determined either by plate count or by membrane filtration. For ophthalmic preparations the European Pharmacopoeia recommends criteria "A", which require e.g. that the bacterial micro-organisms are reduced by a factor of 1000, 24 hours after the challenge. Criteria "B" are still acceptable according to the recommendations of the European Pharmacopoeia, and require e.g. that the bacterial micro-organisms are reduced by a factor of 10, 24 hours after the challenge (for details refer to the European Pharmacopoeia, 1994). Accordingly, whenever the preservative efficacy recommendations of the European Pharmacopoeia are referred to herein, this relates to the 1994 version.

EXAMPLE 15

Diclofenac potassium eye drop formulations

    ______________________________________     diclofenac potassium                         1.00 mg   0.5 mg     tyloxapol USP       1.00 mg   1.00 mg     tromethamine        1.00 mg   1.00 mg     propylene glycol    19.0 mg   19.0 mg     hydroxypropyl-γ-cyclodextrin                         20.0 mg   20.0 mg     disodium edetate    1.00 mg   1.00 mg     benzalkonium chloride                         0.05 mg   0.05 mg     hydrochloric acid 1N                         qs        qs     water for injections ad                         1.00 ml   1.00 ml     pH                  7.96      7.98     osmolality (mOsmol) 305       303     ______________________________________

EXAMPLE 16

Eye gel formulation comprising diclofenac potassium

    ______________________________________     diclofenac potassium                        1.00   mg      1.00 mg     tyloxapol USP      1.00   mg      1.00 mg     tromethamine       6.50   mg      6.50 mg     propylene glycol                  19.0 mg     sorbitol           40.0   mg     hydroxypropyl-γ-cyclodextrin                        20.0   mg      20.0 mg     disodium edetate   1.00   mg      1.00 mg     benzalkonium chloride                        0.05   mg      0.05 mg     carbopol 980       3.50   mg      3.50 mg     water for injections ad                        1.00   ml      1.00 ml     pH                 8.06           8.00     osmolality (mOsmol)                        298            308     viscosity (mPa s)  450            380     ______________________________________

EXAMPLE 17

Eye drops SDU (single dose units, non-preserved)

    ______________________________________     diclofenac potassium                        1.00   mg      0.5  mg     tyloxapol USP      1.00   mg      1.00 mg     tromethamine       1.00   mg      1.00 mg     propylene glycol   19.0   mg      19.0 mg     hydroxypropyl-γ-cyclodextrin                        20.0   mg      20.0 mg     disodium edetate   1.00   mg      1.00 mg     hydrochloric acid 1N                        qs             qs     water for injections ad                        1.00   ml      1.00 ml     pH                 7.95           7.98     osmolality (mOsmol)                        301            300     ______________________________________

EXAMPLE 18

Preservative efficacy

    ______________________________________     diclofenac sodium                      1.00   mg    1.00 mg  --     diclofenac potassium                      --       --       1.00 mg     2-hydroxypropyl-β-cyclodextrin                      15.0   mg    20.0 mg  15.0 mg     2-hydroxyethyl-β-cyclodextrin                      15.0   mg    20.0 mg  15.0 mg     hydroxypropyl-γ-cyclodextrin                      --       --       --     boric acid       13.0   mg    13.0 mg  13.0 mg     borax            8.6    mg    8.6  mg  8.6  mg     methylparabene   0.26   mg    0.26 mg  0.26 mg     propylparabene   0.14   mg    0.14 mg  0.14 mg     sodium hydroxide 0.1N                      8.0    mg    6.0  mg  --     water for injections ad                      1.0    ml    1.0  ml  1.0  ml     pH:              7.80         7.86     7.89     Osmolality (mOsmol)                      332          325      308     preservative efficacy Ph. Eur.                      r.n.m.   r.n.m.   r.n.m.     ______________________________________      r.n.m.(recommendations not met), the preservative efficacy of the      corresponding composition does not meet the recommendations of the      European Pharmacopoeia.

EXAMPLE 19

Preservative efficacy

    ______________________________________     diclofenac sodium --       --       1.00 mg     diclofenac potassium                       1.00   mg    1.00 mg  --     2-hydroxypropyl-β-cyclodextrin                       20.0   mg    --     --     2-hydroxyethyl-β-cyclodextrin                       20.0   mg    --     --     hydroxypropyl-γ-cyclodextrin                       --       20.0   mg  20.0 mg     boric acid        13.0   mg    13.0 mg  13.0 mg     borax             8.6    mg    8.6  mg  8.6  mg     methylparabene    0.26   mg    0.26 mg  0.26 mg     propylparabene    0.14   mg    0.14 mg  0.14 mg     sodium hydroxide 0.1N                       2.0    mg    0.3  mg  0.4  mg     water for injections ad                       1.0    ml    1.0  ml  1.0  ml     pH: (8 ± 0.3)  7.90         7.89     7.92     Osmolality (mOsmol), (300 ± 30)                       323          288      285     preservative efficacy Ph. Eur.                       r.n.m.   r.n.m.   r.n.m.     ______________________________________ 

We claim:
 1. A method of treating inflammatory ocular conditions, or glaucoma, which method comprises administering topically to the eye of a patient requiring such treatment a therapeutically effective amount of an ophthalmic composition comprising diclofenac potassium and a carrier.
 2. The method of claim 1 wherein said ophthalmic composition further comprises a stabilizer.
 3. The method of claim 1 wherein said ophthalmic composition further comprises a solubilizer.
 4. The method of claim 1 wherein said ophthalmic composition further comprises a stabilizer and a solubilizer.
 5. The method of claim 2 wherein said stabilizer is a cyclodextrin.
 6. The method of claim 1 wherein said ophthalmic composition comprises from 0.000001 to 5% by weight of diclofenac potassium. 